The original A-round investors dipped into their wallets again, taking total funding north of $23m. The company is building out a global set of clustered data centres called the Storage Delivery Network. There are currently five nodes in the US, Europe and Asia. Nirvanix says the SDN, with a single global namespace in its Internet Media File System, supports millions of users and billions of files.

Jim Zierick, Nirvanix president and CEO, said: "This latest round of funding will allow us to expand the business to take advantage of the opportunities we have uncovered working with our existing customers." That could mean enabling its data centres to store more data, building more nodes or adding new service interfaces.

The company was founded in 2007 and is based in San Diego, California. In June last year it announced an enterprise offering and added NFS and CIFS interfaces to its service, providing a cloud NAS facility. Users attach the SDN to a local network as a Windows (CIFS, Windows Server 2003, Microsoft Windows XP) or Linux filer (NFS, RedHat 5 or Suse 10) and can then work with the applications they are accustomed to, or drag and drop files from their desktops to the SDN CloudNAS.

One of the B-round investors, Bryan Wolf, managing director of Intel Capital, said: "We are confident that continued investment in Nirvanix will result in increased opportunities in a rapidly expanding industry."

Nirvanix has some 500 customers, ranging from internet start-ups to Fortune 10 companies. Supplier interest in the cloud storage market is growing with Amazon, EMC, Google, Microsoft, Sun, Symantec and other very large suppliers putting money into cloud storage service infrastructure build-out, alongside newbies like Nirvanix and Parascale.

Judging by the B-round funding it looks like we are still very much in an investment phase, with service expansion not being fundable from customer revenues alone. ®